WWI was a trajedy for all countries involved. What made it stand out from any other war that had happened so far was that it involved more than just two countries fighting against each other. Most of the world was involved in the war. There were alliances between many of the countries as well so instead of fighting alone and fending for yourselves as a country, you could have five or even six times as many troops on your side. This however, brought many more casualties along with a longer battle.
Links:
The Red Scare